Investigators believe the pair were killed in an apparent robbery attempt that occurred while Miss Straub’s parents were on a Caribbean cruise. The sheriff’s office said at the time that the crime was not a random act of violence and that Miss Straub and Clarke were targeted.

Maytee Vasquez-Clarke, Johnny Clarke’s mother, said she was stunned when detectives called her with news of the arrest. “I’m in shock. I’m numb. My heart’s beating 140 beats per minute,” she said.